The Royal Family has a hospital in Hong Kong. Prince of Wales Hospital.
Maybe there is human trafficking or organs sent from Hong Kong to SFO.
IDK - just throwing this crazy idea out with delusion of sleep hitting me.
William could have been meeting someone or arranging something.
It doesn't mean he actually flew to or from SFO.
He has the reddish brown hair (and hair cuts change)
He wears a ton of blue shirts (almost every photo I find)
He rolls up his sleeves a lot.
Watch on left arm
Long legs, etc.
look at the hair color